Grinder fixture



Nov. 1, 1960 A. E. MUELLER GRINDER FIXTURE 3 Sheets-Sheet 1 Filed May 9,1958 Q mm \w Jmm 1N VEN TOR. JAV/A/ E. MUELLEI? A. E. MUELLER GRINDERFIXTURE Nov. 1, 1960 3 Sheets-Sheet 2 Filed May 9, 1958 wa n Wm MY.

INVENTOR. 44 V//\/ 5. M05445? a .UQQWQ a w Q. m ,m i

Nov. 1, 1960 A. E. MUELLER 2,958,167

GRINDER FIXTURE Filed May 9, 1958 s Sheets-Sheet :5

INVENTOR. AL V/A/ E. MUEL LE1? ATTwQA/EK GDER FIXTURE Alvin E. Mueller,Downey, Calif., assignor of one-half to Seth Silver-man, Los Angeles,and one-half to Sydney Dock, Glendale, (Calif.

Filed May 9, 1958, Ser. No. 734,320

12 Qlainis. (Cl. 51-232) This invention relates to a grinding fixturesuch as employed to hold a tool, the point of which is to be applied toa grinding tool or the like.

The point of the tool is usually provided with a conical face which isbroken through by relief recesses spaced equidistant apart around theperiphery of the tool.

Such a fixture is usually provided with means for shifting the holderfor the tool along its longitudinal axis so as to withdraw it from theface of the grinder when the recesses are passing the location of thegrinding face and to apply the helical edges of the conical faces of thetool to the grinder face while the tool is being rotated on its axis. Aprincipal object of this invention is to provide improved cam means foreffecting these shifting movements along the axis of rotation of thetool.

Another object of the invention is to provide a cam employed with asolid body, of arc form movably mounted, and provided with means foradjusting the camwith respect to the axis of the tool so that theconical working face of the cam when displaced into different positionsof adjustment, will effect a change in the amount of movement thatoccurs when the cam effects the shifting of the tool longitudinally onits axis.

Another object of the invention is to provide improved cam followermeans to cooperate with the working face of the cam, and including pinsas contact means, which pins may be of a number to correspond with thenumber of relief recesses that are on the tool thatis to be ground. Forexample, two, three or even four relief arcuate faces and four flutes.

While the accompanying drawing and thedescription in this specificationare .concernedprincipally with the 'point of a tool that is to beground,it should be understood that the invention is also applicable where theface or faces on the tool that are to be ground are not necessarilylocated at the point of the tool; and itshould be understood that themovement effected by the functioning of the cam is preferablysupplemented by a spring that is compressed by the movementeffected .bythe cam and operates as a return spring to give the tool being groundthe reciprocating movement which it should have.

While this invention is concernedpri-ncipally with the form and mannerof adjustmentof the cam itself, the invention as described herein isconcerned also with the novel features of the follower pins that run onthe wor ing face of the cam.

Further objects of the invention will be evident from a careful readingof the present specification .and study of the drawing accompanying thesame.

The invention resides in the novel parts and combination of parts, allof which cooperate to produce an efficient grinding fixture.

A preferred embodiment of the invention is described in the followingspecification while the broad scope of the invention is pointed out inthe appended claims.

In the drawing:

Figure l is a longitudinal vertical section taken through mm o thecasing of the grinder showing the tubular spindle partly in sectionandpartly-in elevation, and also showing a boring tool having a conicaltip illustrated as being applied to the face of a grinder wheel. In thisview the upper portion of the casing is broken away to show it insection, while the base portion of the casing is shown in sideelevation.

Figure 1a is a fragmentary view and is a section taken in a radial planethrough the axis of the spindle of the fixture shown in Figure 1. Thisview illustrates in detail the means employed for securing the camfol-lower collar to the sleeve that surrounds the spindle.

Figure lb is a horizontal section on the line 1b1b of Figure 1.

Figure 2 is a vertical section taken onthe line 22 of Figure l, andfurther illustrating the cam of my invention, and its mounting thatenables it to be cocked into different positions to vary, and regulate,the length of the shifting movement that the cam imparts to the sleeveand spindle while being rotated.

Figure3 is a vertical cross section taken on the line 33 of Figure 1,and particularly illustrating a connection between the casing and thespindle that enables the casingyand spindle to be non-rotatablyconnected together-or'free of each other when desired.

Figure 4 is a front elevation of the cam and showing it in an extremelycocked position and also indicating the path of the contact pin or pinsthat may be along the cam when in this position.

Figure 4a is a detail end viewof the right end of the cam and showing anadjacent portion of the body of the cam broken away.

Figure 5 is a perspective of one of the follower pins that run on theworking face of the cam.

Figures 6, 7, and 8 are perspectives which show, respectively, theannular pin .carrier with pins which may be four in number as in Figure6, or three in number as in Figure 7, or two in number as in Figure 8,and showing the equidistant spacing of all of the pins in these views.

Figures 9, 10 and 11 are diagrammatic views that illustrate in thismanner the reciprocating movements of the tool carrier elements andwhere these movements occur in a single cycle of rotation of the toolbeing ground.

Figure 12 is a fragmentary view broken away to show a modified form.

Figure 13 is a vertical section on the line 13-13 of Figure 12.

In practicing the invention we provide a fixture casing 1 that isillustrated as having an indexing hub 2, which is mounted to rotate onan indexing base 3, which is mounted on an anchoring base 4 havingoppositelydisposed bifurcated lugs 5, on which bolts and nuts areattached to clamp the fixture on a working face plate at a point near arotating grinder having a grinder face .6 in proximity to the fixturewhich may carry a tool 7 with a drilling end 8, for example, a pluralityof conical faces 9 with cutting edges 10 spaced equidistantly from eachother, and separated by relief flutes 11.

In this view the direction of rotation of the toolin driving it and itsdirection of rotation when at work is indicated by the arrow 12.

The tool illustrated has a shank 13 which is shown as clamped betweenjaws of a collet 15, which is of tubular form and provided with threeslots such as the slots 1-6 that extend a considerable distancethroughout the length of the collet.

The inner end of the collet is provided with. screw threads 17 by meansof which it is attached to the forward end of a tubular spindle 18'. Thethread 17 of the ,p p r V 3 l spindle" engages thread in a counterboreat 19, so that an annular shoulder 20 is formed near which the end ofthe collet may approach but not seat upon.

I However, .When the inner end of the collet has proper clearance at theannular shoulder 20 a conical counterbore 21 on the forward end of asleeve 22 enables contacting inclined conical faces of the jaws,14 toclamp the shank 13 of the tool securely between the jaws by rotatingthebore wheel 27.

This sleeve 22 encompasses the tubular spindle 18 with its rear end 23located near the rear end of the casing 1. .The tip of this extension 23has a conical 'counterbore 24, which operates as a seat 25 for aconition.

With the construction described, it will be evident that if the sleeve22 is held against rotation, then rotation of the spindle 18, by meansof the hand wheel can be made to draw the collet further into theforward end by reason of the presence of the thread 17 alreadydescribed.

This operation enables the tapered seat 2'4 and the conical countcrbore21 at the forward end of the fixture to cooperate to clamp the shank 13of the tool by means of the jaws at the forward end of the collet. InFigure 1 I illustrate means shown in section in Figure l and also insection in Figure 3. This means preferably includes a pin 30 and thispin is rigid with a head 31 on its outer end, but slides freely througha drilled hole in a hexagon nut 32, or the like which has a threadednipple 33 that can be screwed into a threaded socket 34 so as to seatthe face of the nut 32 on a small horizontal face or pad 35 on the upperside of the casing 1.

The lower end of the pin 30 is secured to a tip 36 the upper face ofwhich operates as a seat for a coiled spring 37 that thrusts on itsupper end against the lower end of the nipple 33, so as to bias the tip36 towards the sleeve 22. In Figure 1 the pin 30 is shown in its lockingposition in which it is depressed sufliciently to enable its extreme endin the form of a button 38 to project into a slot 39 which extendslongitudinally through the material of the sleeve and parallel with theaxis of the spindle.

When desired, however, the pin head 31 can be pulled upwardly androtated on its axis through ninety degrees. This enables twodiametrically opposite abutments 40 which are tapered to edges 41 toseat themselves on the upper end face 42 of the nut 32. When in thisposition the button 38 will be held clear of the slot 39 and this, ofcourse, will enable the spindle 18 with the sleeve 22 tight on it to berotated freely by the operator of the fixture by means of the handle 29.

Of course, this is the relation of the parts while the operator of thefixture is conducting a grinding operation.

In this connection it should be understood that the face 6a of thegrinding wheel is disposed at an angle to the axis of the tool 7 so thatwhen the tool approaches the grinding wheel to apply one of its conicalfaces 9 to the face of the grinder, the elements of the conical face asthey pass the face 6a will be parallel to it. In other words, when theconical faces are against the grinder face they will be tangent to itsperiphery.

The forward end of the sleeve 22 projects a considerable distance fromthe forward end of the casing 1, and this part of the sleeve is providedwith an annular shoulder 43; and against this shoulder abuts the rearface 44 of a cam follower comprising a collar 45. This collar carries anextension or extensions to run on a cam 46 that is attached to a face 47that is recessed back into the forward end of the casing. This campresents a conical face 48 on which the extension part or parts on thecollar run when the spindle is rotating beneath the extension partmoving around with it.

In the present instance I provide 2, 3, or 4 contact pins 49, the shanksof which have flat faces 50 engaged by the tips of the set screws 51,that clamp the different pins 49, but before the set screws 51 aretightened up other set screws 52 threaded into the forward faces of thecollar 45' are adjusted up far enough to have the tips of the pins justtouching the face of the cam.

The projecting ends of the pins are formed with inclined flat side faces53 so that the extreme end of each pin resembles a chisel edge; that isto say, each pin, as indicated in Figure 5, presents an edge 54- atwhich the fiat side faces 53 form an acute dihedral angle.

However, this edge 54 has a pitch of proper degree to enable it to abutclosely to the face of the cam now about to be described.

Referring now particularly to Figures 1, 2, .and 4, it will be evidentfrom these views that this cam 55 is of arcuate form and mounted foradjustment about the was of a pivotal socket 56 which has a drilled holeextending in through the face 47. In practice I prefer to provide awrist pin 57, the forward end of which has a threaded stud 53 which isscrewed tight into a threaded socket 59 in the rear face of the cam; andjust above the cam the casing '1 projects forwardly and overhangs thecam,

forming a visor 60, which functions to provide a mountthe pins 49 intracking around on the inclined forward face 55a of the cam will bepassed in an are along a medial line midway between the inner and outeredges of the cam face 55:: and consequently, the cam will not shift thepins, nor the spindle forward.

However, if the set screws 61 and 62 are adjusted to place the cam in acocked position, with one end of the cam nearer to the path of the pins49, and its other end further from their path, such as indicated in thedotted lines 55b (see Figure 2), then as the pins 49 pass upwardly atthe right they will be near the inner edge of the cam, but as they leavethe carns face, they will be quite near the outer edge of the cam.Hence, as the cam is thicker at its outer edge, each pin that passes inthis way will be shifted by the cam toward the left, as viewed in Figure1, and this, of course, will cause the tool to approach and contact theface 6a of the grinder. The line 550 shows the path of the pins in thecocked cam.

The cam extends through more than degrees of arc, and this arc should beslightly greater than 180 degrees, and at least sufficiently long toinsure that even with two pins only on the cam follower, before any pinleaves the face of the cam another pin will have landed on the drivingface of the cam.

As the spindle shifts forwardly, means provided on the fixture that isbiasing the spindle and sleeve 22 toward the rear operates to return thespindle and of course, the tool 7, to the position it had when thecontrolling pin 49 encountered the driving face of the cam as it wasrevolving past it. In the present instance, in order to accomplish thisthe rear end of the casing is provided with a counterbore 63 .thathouses coil spring 64, the rear end of which thrusts against a bushing65 that is adjustably mounted on the projecting rear end 23 of thesleeve 22, which can be attached and secured in any desired position bymeans of a set screw 66.

Referring again to the collar 45, of the cam follower, the meansemployed to secure the same against the shoulder 43 will now bedescribed. Referring particularly to Figure la in connection with Figure1; on the latter figure a V-type groove 67 is provided encircling theforward end of the sleeve 22 close to the shoulder 43, and at twoopposite points on the collar 45 two set screws ahead-"e7 such as theset screws 68 are provided. These set screws have conical tips turned ata smaller angle at their tips than the angle at which the V-shape groove67 is cut. These pins are located so that when tightened up they willland in the cut on the face 69a of the same, that is remote from theshoulder, thereby forcing the inner face of the collar up against theshoulder.

Referring again to the wrist pin 57, (Figure 1), a similar V.-shapegroove 69 extends around the waist of the wrist pin 57 to receive aconical tip on the set screw 70 that is seated in the tapped hole 71extending down through the top side of the casing at this point. Thisset screw should be tight enough in the groove to hold the rear face ofthe cam seated up against the vertical forward face 47 of the casing 1.

In Figures 12 and 13 there is illustrated means associated with a cam55a which enables the cam to be shifted by a movement of translation soas to displace the cam bodily from its neutral position. When displacedin this way the cam is displaced from its neutral position and is thenout of line with the axis 72, about which the cam follower rotates.

Such a displacement by a movement of translation may be, of course,effected in a verticalor a horizontal position, but in Figures 12 and 13the means indicated for effecting the displacement operates to displacethe cam by a movement of translation in a horizontal direction, as thatis more adaptable to the fixture illustrated in Figures 1 and 2.

In order to accomplish this the visor 60a, as shown in Figure 12, at oneend is slightly modified from the visor form shown in Figure 2. This isdone so that it will present a relatively long vertical end face 73,through which a stem 74 passes in a horizontal direction. In order toaccomplish this two drilled holes 75 and 76 are formed through thevertical face 73, and also through a similar vertical face 77 at theother end of the visor. These drilled holes operate as bearings for thestem 74.

In line with the two bores 74 and 76 a tapped drilled hole 78 is formedthrough the material at the crown 79 of the cam 55a, that is to say, atthe middle point of the arc of the cam. This drilled hole 78 is ofslightly larger diameter than the drilled holes 74 and 76 so that whenthis drilled here is tapped, a thread cut into its wall can cooperatewith upset thread 70 on the middle portion of the stem 75. The ends ofthe stem 74, of course, have their bearings in the material at the endsof the visor 60a.

In order to facilitate drilling the relatively larger bore 78 where itis located I prefer to rout out two recesses 80 and 81 equidistant fromthe middle point of the arc of the cam 55a, in order to have the campresent two vertical faces 82 which will facilitate starting the drillof this bore 78.

When the stem 74 is passed in through the drilled hole 75 from the left,as viewed in Figure 12 and also passed through the oversize opening 78of the .cam until the upset thread engages the threads cut into theslightly oversized drilled hole; the stem 74 is then rotated to bringthe upset thread into the thread of the oversized opening, while guidingthe tip of the stem into its bearing opening 7 6.

A collar 83 is then screwed onto a threaded reduced tip 74a andtightened up against a split spring washer 84 thatseats on the annularshoulder at 84a located at the root of the reduced tip 74a. The washer84 seats against the end face 77 of the visor 60a.

At the other end of the stem 74 an indexing head 85 is provided having ahub 86 with a dowel 87 let into the face 73 to keep theindexingheadproperly aligned.

On the end of the stem 74 a knurled knob 8'8 is.'car ried, having ascribe'line 89 that cooperates with a scale on the indexing head 85,when adjustments are being effected on the cam 55a.

part of the spindle.

-In connection with Figure 13 it should be noted that the flat rear faceof the cam 55a is'constantly :held pressedupon the vertical face 91 atthe forward end of the casing 92 of the 'fixture "by the'pressureexerted by the cam follower pins; and it should be remembered thatthere' is always one or more of the cam follower pins 93 running acrossthe working face 94 of the cam.

With the degree of adjustment of the 'cam indicated in 'Figure 12, the.cam follower pins 93 will describe a path about as indicated by thebroken line 95.

This fixture is provided with means that can be employed to shift thespindle with the sleeve 22 tightened on it by means already describedherein above.

It may be desired occasionally to effect a forward shifting of the camfollower to remove it sufficiently to enable the spindle and sleeve tobe rotated by the handwheel, or other means, freely and eliminating thenormal functioning of the cam follower and the cam.

In other words, such a transformation in the mode of operation could'beused to permit a tool to be held in the collet and rotated freely on itsaxis as though mounted in a'lathe chuck.

In order to accomplish this the sleeve 22, should be tightened on thespindle; then it becomes virtually a The .outer surface of the sleevehas been previously provided with a circumferential slot 96 (see Figures1 and 111). And the casing 1 on its right side and at the level of itshorizontal axis is provided with a set screw97 located a short distanceforward of the circumferential groove 96.

'compressingthe spring 64, and finally aligning the groove 86 with areduced'tip 103 at the forwardend of the setscrew97; while being held inthis relation the set-screw is rotated to advance the tip 103 into thegroove 96, and in this positionthe cam follower collar 45 and itsfollower'pins 49 can he held clear of the cam 46 to permit free rotation'of the cam follower without any interference from the cam .as the samecam follower rotates.

Many other embodiments of this invention maybe resorted to withoutdeparting'from the spirit of the invention I claim as my invention, anddesire to secure by Letters Patent:

1. In a grinder fixture for holding and applying a tool to be ground, tothe abrasive face of a grinder, the com bination of a casing, a chuckfor clamping the tool with its axis coinciding with the axis of thechuck, a spindle rotatably mounted in the casing, and carrying thechuck, a cam having a conical driving face, means for supporting the camso that the said conical driving face is coaxial with the axis ofrevolution of the spindle, means for supporting said spindle so that itis shiftable along its own axis, a cam follower secured to rotate inunison with the spindle, and having a contact part capable of engagingsaid conical driving face along a contact path coinciding with themedial arcuate line of said driving face, and approximately in a planemaking approximately a right angle with the geometrical central axis ofthe cam, and means for effecting an adjustment of said cam into alaterally displaced position in a plane extending transversely to theaxis of rotation of the spindle and the tool, and thereby causing thesaid contact part to engage the driving face of the cam along a' newpath lying approximately-in a plane that deviates from the approximateplane in which said medial line lies, and thereby altering the length oftravel of the tool toward and from the abrasive face of the grinder anamount approximately proportionate to the degree of said adjustment.

against said driving face of said cam.

3. A grinding fixture for holding and applying a tool to be ground, tothe abrasive face of a grinder, according to claim 1, in which thedisplaced positions for the cam with respect to the axis of the rotationof the tool includes means for effecting 'the adjustment of the camabout a pivotal support on the geometric axis of the face of the cam,thereby displacing the cam into a cocked position about said axis.

4. In a grinder fixture for holding and applying a tool to be ground tothe face of a grinder, according to claim 1, in which the said cam is ofblock-form and mounted for rotation on a pivot to facilitate itsadjustment into the cocked position.

5. In a grinder fixture for holding and applying a tool to be ground toa grinder face, according to claim 1, including a tubular sleeve coaxialwith the spindle and surrounding the same, and in which the chuckcomprises a collet having a thread connection at the forward end portionof the spindle, said collet having spaced apart jaws at its forward endhaving inclined circumferential faces on the jaws; the forward end ofsaid sleeve having a tapered counter-bore in which the tapered faces ofsaid jaws seat, the rear end of said spindle and the rear end of saidsleeve having abutting faces cooperating as a seat for the rear portionof the spindle, said sleeve having a longitudinal slot in' the outerface thereof, and spring- '-loaded detent pin means with a tip biased bythe spring toward the sleeve for tightening the collet and locking thesleeve against rotation within the casing, an actuating part rigid withthe spindle at the rear end of the casing for rotating the spindle, saiddetent-pin means tip operating when in the said slot, to enable therotation of the manually operated part to loosen the collet in thesleeve;

said detent-pint means having means functioning upon rotation of thesame to hold its tip withdrawn from the slot.

6. A grinding fixture for holding and applying a tool to be ground, tothe abrasive face of a grinder, according to claim 1, in which the meansfor adjusting the cam into different displaced positions with respect tothe axis of rotation of the tool consists of means for shifting the camlaterally by a movement of translation with respect to the axis ofrotation of the contact part.

7. A grinder fixture according to claim 1, in which the cam followerincludes a cam body and said contact part comprises a pin secured to thecamrbody and projecting toward the plane in which said driving facelies, said pin having a chisel-form tip presenting an edge lying in aplane extending about radially to the axis of rotation of the cam body.

8. In a grinder fixture for holding and applying a tool to be ground, tothe face of a grinder, the combination of acasing, a chuck for clampingthe tool, a spindle rtatably mounted in the casing, and carrying thechuck, a cam having a conical driving face, means for supporting the camso that the conical driving face is coaxial with the axis of revolutionof the spindle, means for supporting said spindle so that it isshiftable along its own axis, a cam follower secured to rotate in unisonwith the spindle, and having a contact part capable of engaging saidconical driving face and contacting the same along an arc, and means foradjusting said cam into a cocked position in which the axis of theconical driving face is eccentric to the axis of rotation of thespindle, whereby the said contact part engages the said driving facealong a line inclined with respect to the transverse plane in which saiddriving face lies, thereby effecting the shifting -movement of saidspindle and said tool with respect to the grinder face.

it is 'shiftable' along its cam axis, a cam follower secured to rotatein unisonwith the spindle, and having a contact part capable of engagingsaid arcuate driving face and contacting the same along an arc, andmeans for adjusting said cam into a cocked position in which the axisof'the conical driving face is eccentric to the axis of IO- tation ofthe spindle, whereby the said contact part engages the said driving facealong a line inclined 'with'respect to the transverse plane in whichsaid drivingfa'ce turns, thereby effecting the shifting movement of saidspindle and said tool with respect to the grinder face.

10. A grinder fixture according to claim 9, in which the said contactpart is a pin, and in which the cam body and the pin have cooperatingmeans for preventing rotation of the pin on its own axis, therebymaintaining the said edge in its radial plane with respect to the axisof the cam body. a

ll. In a grinder fixture for holding and applying a tool to be ground,'to the face of a grinder, the combination of a casing, a chuck forclamping the tool, a spindle rotatably mounted in the casing, andcarrying the chuck, a cam having a conical driving face, means forsupporting the cam so that the conical driving face is coaxial with theaxis of revolution of the spindle, means for supporting said spindle sothat it is shiftable along its own axis, a cam follower secured torotate in unison with the spindle, and having a contact part capable ofengaging said conical driving face and contacting the same along an arc,and means for adjusting said cam into a cocked position in which theaxis of the conical driving face is eccentric to the axis of rotation ofthe spindle, whereby the'said contact part engages the said driving facealong a line inc-lined with respect to the transverse plane in whichsaid driving face lies, thereby effecting the shifting movement of saidspindle and said tool with respect to the grinder face.

12. In a grinder fixture for holding and applying a tool to be ground tothe face of a grinder, the combination of a casing, a chuck for clampingthe tool, a spindle rotatably mounted in the casing, and carrying thechuck, a cam having an arcuate driving face inclined with respect to theplane of rotation of the cam follower, means for supporting the cam sothat the said driving face is coaxial with the axis of revolution of thespindle, means for supporting the said spindle so that it is shiftablealong its own axis, a cam follower secured to rotate in unison with thespindle, and having a contact part capable of engaging said arcuatedriving face and contacting the same along an arc, and means foradjusting said carn into a cocked position in which the axis of theconical driving face is eccentric to the axis of rotation of thespindle, whereby the said contact part engages the said driving facealong a line inclined with respect to the transverse plane in which saiddriving face turns, thereby eifecting the shifting movement of saidspindle and said tool with respect to the grinder face.

References Cited in the file of this patent UNITED STATES PATENTS1,981,174 Hille Nov. 20, 1934 2,004,283 Hurt June 11, 1935 2,196,416Jacob Apr. 9, 1940 I 2,249,656 Huband July 15,1941 2,325,364 Boeniug .aJuly 27, 1943

